From the Guidelines
A protein-restricted diet is indicated for patients with chronic kidney disease (CKD) stages 3-5, with or without diabetes, to reduce the risk of end-stage kidney disease and improve quality of life. The primary indications for a protein-restricted diet include:
- Chronic kidney disease (CKD): Patients with moderate to severe CKD (stages 3-5) often require protein restriction to reduce the workload on the kidneys and slow disease progression, as recommended by the KDOQI clinical practice guideline for nutrition in CKD: 2020 update 1.
- The level of protein restriction varies depending on the condition and its severity, with typical recommendations for CKD ranging from 0.55-0.60 g of protein per kg of body weight per day, or a very low-protein diet providing 0.28-0.43 g dietary protein/kg body weight/day with additional keto acid/amino acid analogs to meet protein requirements 1.
- For CKD patients with diabetes, a dietary protein intake of 0.6-0.8 g/kg body weight per day may be prescribed to maintain a stable nutritional status and optimize glycemic control, as suggested by the KDOQI clinical practice guideline for nutrition in CKD: 2020 update 1. It's crucial for patients on protein-restricted diets to work closely with a registered dietitian to ensure adequate nutrition while adhering to the prescribed protein limits, and regular monitoring of nutritional status is essential to prevent malnutrition. The rationale behind protein restriction in CKD is to reduce the accumulation of nitrogenous waste products, which can exacerbate symptoms and accelerate disease progression, as supported by the KDOQI clinical practice guideline for nutrition in CKD: 2020 update 1.
From the Research
Indications for a Protein-Restricted Diet
The indications for a protein-restricted diet include:
- Chronic kidney disease (CKD) patients to decrease the accumulation of nitrogen waste products, hydrogen ions, phosphates, and inorganic ions while maintaining an adequate nutritional status 2, 3, 4, 5
- Patients with chronic nephropathy and renal insufficiency to slow the progression of chronic kidney disease and impaired renal function 6
- Patients with advanced hepatic encephalopathy, with moderate restriction of protein intake (0.5 - 1.2 g/kg body weight/day) and possible addition of branched chain amino acids (BCAA) 6
- Patients with CKD to reduce albuminuria and prevent uraemic symptoms 2, 5
Benefits of Protein-Restricted Diets
The benefits of protein-restricted diets include:
- Lowering serum urea nitrogen levels 2
- Improving phosphocalcic metabolism and insulin resistance 2
- Ameliorating proteinuria (independent of antiproteinuric medications) 2
- Delaying the initiation of renal replacement therapy 4
- Improving outcomes in CKD patients 4
Special Considerations
Special considerations for protein-restricted diets include:
- Patients with chronic renal failure undergoing renal replacement therapy by hemodialysis or peritoneal dialysis require an increased protein intake to prevent protein-energy malnutrition 6
- Patients with cirrhosis of the liver should not have their protein intake diminished, but rather increased to 1.0 - 1.2 g/kg body weight/day to prevent protein malnutrition 6